CXCL12 and myeloproliferative neoplasm: Thereafter we established co-culture of hTERT and HS5 with UKE cells, SET cells (MPN cell line) and with CD34+ cells (HD), to study the alterations in the expression of important genes (CXCL12, NF-ƘB and Angiopoetin1) induced by leukemic cells.